I don't know," says Bruno Mars, kicking back in the opulence of a penthouse suite at the five star Sanderson Hotel on London's West End, "if it ever goes down like this."

The following day he'll play a blistering late-afternoon show to 64,000 sun-kissed British fans at the Wireless Festival (sponsored by Barclaycard), held in the U.K. capital's Hyde Park. But for now, the 25-year-old Hawaii native is enjoying a rare day off and reflecting on a "crazy surreal" journey that has seen him climb from childhood Elvis impersonator to the brink of global superstardom.

"It's a rare thing that happens," he says, a packet of cigarettes and a smartphone resting by his feet, "especially in this day, where it's real hard to sell albums. I'm traveling to places that I've never even heard of and there are all these people singing the songs back -- and English is not even their first language. It's like, what the hell happened?" The answer is simple: Music fans the world over have fallen in love with Bruno Mars.

Mars' debut album, "Doo-Wops & Hooligans" (Elektra), has spent 39 weeks in the Billboard 200's top 40. It debuted at No. 3 the week of Oct. 23, 2010, and has sold 1.2 million units in the United States, according to Nielsen SoundScan. First single "Just the Way You Are" spent four weeks atop the Billboard Hot 100, moving 4.5 million copies. The touching, R&B-flavored track also spent 20 weeks at No. 1 on the Adult Contemporary chart -- the longest-reigning debut single in the list's 50-year history. His follow-up release, "Grenade," reached No. 1 on the Hot 100 on Dec. 30, 2010, and has moved 4.4 million U.S. copies. "The Lazy Song," the third track off Doo-Wops, peaked at No. 4 on June 18 and has sold 2 million downloads.

Mars' appeal isn't just limited to the United States. "Doo-Wops" hit No. 1 in the United Kingdom, Canada, Germany and Ireland. The United Kingdom has proved a particularly fertile market -- he's scored three No. 1 singles with "Way," "Grenade" and "Lazy," selling a combined 2.2 million U.K. units, according to the Official Charts Co. The OCC places Doo-Wops' U.K. sales at 620,000. The eclectic 10-track album, which mixes pop, soul, soft rock, reggae and swing, has been certified 14 times platinum worldwide, according to Elektra. Mars' total worldwide single sales stand at 15 million, the label says. And then there's his other job: with Los Angeles-based production trio the Smeezingtons.

Made up of Mars and fellow songwriter/producers Ari Levine and Philip Lawrence, the Smeezingtons are a six-legged pop phenomenon, scoring a succession of Hot 100 smashes in the past two years, including 2010's "Nothin' on You" by B.o.B featuring Mars (2.8 million, according to SoundScan). Other credits include last year's "Billionaire" by Travie McCoy featuring Mars (2.9 million) and "F**k You (Forget You)" by Cee Lo Green (4.9 million), and the recent "Lighters" (314,000 units) by Bad Meets Evil, aka Eminem and Royce Da 5'9", that features Mars. The Smeezingtons also wrote and produced Doo-Wops, while Mars and Lawrence helped co-write Flo Rida's 2009 Hot 100 No. 1 "Right Round" (4.9 million).

To paraphrase the man himself, it doesn't normally go down like this. Ever. "That's because the world has never seen another Bruno Mars," the charismatic singer jokes, before imploring, "Please let that be the headline."

"He's a quadruple threat," Elektra Records co-president John Janick says. "He's a writer, a producer, an amazing singer and an amazing performer -- on top of that he just has a great personality."

"The great thing about Bruno is that you can't put him in a box. That's why I think people are so attracted to him and his music," Atlantic Records chairman/COO Julie Greenwald says. "You can put him with any type of artist from any genre and it will be beautiful. He understands music." To understand the roots of Mars' musical education one must go back to the late '80s when he made his onstage debut, at age 4, impersonating Elvis Presley in his parents' 1950s-style revue on Honolulu's Waikiki Beach. "That was it," Mars says. "I was Elvis."

He was born Peter Gene Hernandez in Honolulu to a Filipino singer and a Puerto Rican-born percussionist raised in Brooklyn. Young Peter moved to Los Angeles in his late teens. He regularly played shows at dive bars on Ventura Boulevard. "To about six people," he says. "All related, of course." Bruno eventually landed an artist deal with Universal Motown, only to be dropped a year later. "I wasn't ready for it," he says. "I did nothing. And the lesson was -- why are you waiting for someone to come and write a song with you? You know how to play the freakin' guitar. Do it on your own." At around this time he met Philip Lawrence, a fellow struggling, broke songwriter, who was attempting to break into the music industry.

"We immediately hit it off because we have such a similar musical sensibility -- we're very melody-driven," Lawrence says. "He plays every instrument, so he comes from that very musical world. I come up with the big melodies and the big hooks and it just comes together somehow." Teaming up to write songs for other artists, the Smeezingtons -- the term "smeez" is a pun on "smash" -- were born, soon to be joined by New Jersey native Ari Levine. Mars' future manager, Brandon Creed, then VP of A&R at Epic Records, gave the production outfit an early boost when he bought one of their songs for $20,000 for an undisclosed pop act.

"That kept us afloat," says Mars, who credits Creed with guiding his artistic development. "Brandon was always saying, 'You need a story. You need to be in the studio writing for people.' At the time I was like, 'You're crazy. I'm amazing!' But he was absolutely right. Working and interacting with other artists and being so involved with the business aspect; understanding A&R, understanding radio, understanding music videos meant that when it came to my time, I'd seen how it goes."

Not everyone in the industry shared Creed's faith. Mars says he was turned down by every label before the newly revived Elektra Records, according to him, "rolled the dice and hit the fucking jackpot." "There was a lot of rejection," he says. "A lot of other labels saying, 'You don't know who the hell you are. You're doing all this reggae, R&B, rock stuff. How the hell do we market that? Are you pop? Are you urban?' Elektra gave me a shot and trusted my vision."